Cycle between normal, black & white and blurred version of desktop wallpaper while in Launchpad

Launchpad in OS X Lion brings the iPad’s user interface to the Mac. Apps that are installed from the App Store or into Applications folder will appear in Launchpad. While in Launchpad, you can toggle between normal, normal blurred, black & white and black & white blurred version of desktop wallpaper by pressing Command+B key.